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Chemical collection and stock control for UK schools, universities and hospitals

Dimethylformamide (CAS 68-12-2): storage and disposal

Dimethylformamide, better known as DMF, is a flammable polar solvent held as a neat liquid in school, college and university stores. It is harmful in contact with skin and if inhaled, causes serious eye irritation and may damage the unborn child. In a university prep room it tends to sit alone at the back of a cabinet and be used rarely, so old, half used bottles are the usual finds at clear-out.

CAS number
68-12-2
Form
Liquid
Storage class
Flammable
Signal word
Danger
Usual EWC code, laboratory stock
16 05 06*
  • Flammable pictogramFlammable
  • Harmful or irritant pictogramHarmful or irritant
  • Serious health hazard pictogramSerious health hazard

What to do this week

  1. Without moving anything that looks damaged, check the label is readable and write down the opened date if it is not already there.
  2. Check it is stored as flammable stock, and apart from anything listed under "Do not store with" on this page. If nothing is listed, that does not prove it is safe with everything.
  3. If you no longer need it, add it to your disposal list so it can be included in a collection.

Safe storage in a school or lab

Because it may damage the unborn child, access matters as much as the cabinet. Keep it in a ventilated fire-resistant cabinet with spill containment, away from ignition sources, and make sure staff who may be pregnant know it is there before they handle it. Nitric acid reacts violently with organic solvents and can ignite them or build pressure in waste bottles, and perchloric acid forms explosive mixtures with organic material, so neither should be in the same store. Gloves are needed, since it is harmful through the skin. Keep the cap tight, because DMF takes up moisture, and date every bottle when opened.

How to tell it has deteriorated

An old bottle of DMF slowly breaks down with moisture and forms an amine with a fishy odour. A fishy smell noticed by accident is a warning sign, but nobody should open or sniff a bottle to check. Check the level too, because a flammable liquid in a loosely capped bottle drops over time, and look for a swollen cap liner, a damp neck, stained labels and a tacky shelf. Some plastics and rubber seals soften in contact with it, so a distorted cap is worth noting. A bottle with a fishy smell is listed as aged stock and is not used.

How it is disposed of

We arrange this by specialist collection. We do not publish a drain or general waste route for any chemical. It is normally packed in a flammable laboratory pack with compatible chemicals.

Write down the bottle size, the fill level and whether a fishy smell has been noticed by accident, since a partly decomposed bottle is declared as it stands. Nobody should open or sniff a bottle to check. DMF goes in a lab pack with compatible organic solvents and is described under waste code 16 05 06*, or 16 05 08* for a discarded organic chemical outside a pack. Because it can damage the unborn child, record the full label name, including N,N-dimethylformamide where that name is printed. It is never poured into a sink, never put in the bin and never left to evaporate, and nobody should try to treat it first.

Waste codes for Dimethylformamide
Usual EWC code, laboratory stock16 05 06*
Discarded organic chemical, not a laboratory pack16 05 08*
Usually classed as hazardous wasteYes

20 01 13* (solvents) belongs to municipal collections and is shown for reference only. It is not the normal code for a laboratory collection.

The code depends on where the waste came from and what it contains, and classifying it is the producer's duty. Use the waste code finder to see why.

Do not store with

  • OxidiserOxidisers can ignite flammable materials or make a fire far more intense.
  • AcidSome acids, especially oxidising acids, can ignite flammable materials, and acid fumes attack containers and seals.
  • CorrosiveA leak of corrosive stock can break down flammable containers and feed a fire.

Named chemicals to keep apart

  • Acetic acidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
  • Calcium hypochloriteOxidisers can ignite flammable materials or make a fire far more intense.
  • Hydrochloric acidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
  • Hydrogen peroxideOxidisers can ignite flammable materials or make a fire far more intense.
  • Nitric acidNitric acid reacts violently with organic solvents and can ignite them or build pressure in waste bottles.
  • Perchloric acidPerchloric acid forms explosive mixtures with organic material.
  • Potassium nitrateOxidisers can ignite flammable materials or make a fire far more intense.
  • Potassium permanganateOxidisers can ignite flammable materials or make a fire far more intense.
Show 3 more
  • Sulfuric acidOxidising acids can ignite flammable materials, and acid fumes attack containers and seals.
  • Thionyl chlorideA leak of corrosive stock can break down flammable containers and feed a fire.
  • Zinc chlorideA leak of corrosive stock can break down flammable containers and feed a fire.

Common quantities

Usually held as: neat.

Tell us the container size and how many you hold. An estimate is enough to start with, and some items cannot be priced until someone has looked at them.

Where it is commonly held

Hazard statements

  • H226 Flammable liquid and vapour.
  • H312 Harmful in contact with skin.
  • H319 Causes serious eye irritation.
  • H332 Harmful if inhaled.
  • H360D May damage the unborn child.
Precautionary statements
  • P203 Obtain, read and follow all safety instructions before use.
  • P261 Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264+P265 Wash hands and exposed skin thoroughly after handling. Do not touch eyes.
  • P271 Use only outdoors or in a well-ventilated area.
  • P280 Wear protective gloves, protective clothing, eye protection and face protection.
  • P302+P352 IF ON SKIN: Wash with plenty of water.
  • P304+P340 IF INHALED: Remove person to fresh air and keep comfortable for breathing.
  • P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P317 Get medical help.
  • P318 If exposed or concerned, get medical advice.
  • P321 Specific treatment (see supplemental first aid instruction on this label).
  • P337+P317 If eye irritation persists: Get medical help.
  • P362+P364 Take off contaminated clothing. And wash it before reuse.
  • P405 Store locked up.
  • P501 Dispose of contents and container in accordance with local, regional, national and international regulations.

Substance as classified, dilutions may differ.

Questions

Why does our old DMF smell of fish?

Moisture slowly breaks it down and one product is an amine, which smells fishy. The bottle is aged stock. Keep it capped in the fire-resistant cabinet, avoid opening it, and declare the smell when you list it for collection.

Who should be told before DMF is moved?

Anyone who may handle it, particularly staff who are pregnant or may become pregnant, because it may damage the unborn child. Follow your own risk assessment, wear gloves and keep the cap closed while the bottle is moved.

Can DMF go in the same cabinet as acids?

No. Nitric acid reacts violently with organic solvents and can ignite them, and perchloric acid forms explosive mixtures with organic material. Keep acids in a corrosive store and DMF in the fire-resistant cabinet.

What do we record about a half full bottle?

The full label name, size, approximate fill, date opened if known, and any smell or damage. The collector uses that to pack it with compatible organic liquids.

Guidance only. Check your own risk assessment and your supplier's safety data sheet.

Hazard data source: PubChem GHS Classification, retrieved 31 Oct 2026. Formula C3H7NO. EC number 200-679-5.

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